First of all, the two numbers quoted above by Matt are unrelated metrics. The count of 123 million users is explained in the press release MSN Spaces Now Largest Blogging Service Worldwide which states that comScore Media Metrix has measured the service's reach as being 100 million unique vistors a month and this number is in addition to 20 million unique visitors from using the chinese version of MSN Spaces. The 70 million number is the number of blogs spaces that have been created since inception. This number isn't particularly interesting since it doesn't correlate to how many people are actually getting value out of the service.

According to those statistics only 1 out of 5 LiveJournal accounts is actually active. Of course, it would sound impressive to tout 11 million LiveJournal accounts even though the number of active accounts is much less. For that reason, the number of spaces on Windows Live Spaces isn't a particularly interesting metric to me nor is it to anyone I know who works on the product. We are more interested in the number of people who actually use our service and get value added to their lives by being able to share, discuss and communicate with their friends, families and total strangers.